A bomb blast that ripped through a busy intersection in central Bangkok killing 19 people did "not match" the tactics used by separatist rebels in Thailand's south, the country's army chief said on Tuesday.
"This does not match with incidents in southern Thailand. The type of bomb used is also not in keeping with the south," Royal Thai Army chief and deputy defense minister General Udomdej Sitabutr said in a televised interview.
No group has claimed responsibility for the blast on Monday evening, which left scores wounded, and officials in Thailand have yet to blame any group.
Thailand's three southernmost provinces are home to a long-running Muslim separatist insurgency. Since 2004, more than 6,500 people, most of them civilians, have been killed in violence in the region.
The violence has rarely spilled over beyond those provinces.